Ever since it has been possible to electroplate objects, it has been desirable to be able to remove the electroplated deposit in order to salvage those objects which might have been unsatisfactorily plated. In the case of nickel plating, a number of methods for removing nickel deposits can be found in the technical and patent literature. However, with the recent introduction of commercially acceptable bright nickel-iron alloy electrodeposits (as for example exemplified by U.S. Pat. Nos. 3,795,591 and 3,806,429 to Clauss et al. or 3,804,726 to Passal), the stripping methods which had been successful for removing nickel deposits have proved to be ineffective in removing nickel-iron alloy deposits. Thus, it has not been possible to easily, rapidly or satisfactorily remove these new decorative nickel-iron deposits. This invention describes a method for the rapid and efficient removal of nickel-iron deposits, so that objects which for one reason or another have been unsatisfactorily plated with a nickel-iron alloy, may be stripped of the nickel-iron alloy deposit and salvaged.
Heretofore, it has been possible to strip nickel deposits (whether electrodeposits or electroless) from a ferrous basis metal such as steel or iron because the nickel deposit was sufficiently different chemically and/or electrochemically from the ferrous basis metal so that the stripping action was confined to the nickel deposit and did not attack the ferrous basis metal. However, with the introduction of commercially successful nickel-iron alloy deposits, particularly those with substantial proportions of iron (e.g. 5% or more), the deposit is more chemically and/or electrochemically similar to the ferrous basis metal on which the nickel-iron alloy may be electrodeposited. Thus, those strippers which might be able to dissolve and strip the nickel-iron alloy deposit, cannot differentiate between a ferrous basis metal and the deposit, and thus also dissolve and attack the ferrous basis metal with subsequent damage and/or destruction of the ferrous object which it is desired to strip. Conversely, those stripping solutions which heretofore have successfully been used to strip nickel are ineffective in stripping the new nickel-iron alloy deposits. As a result, a satisfactory method for stripping nickel-iron alloy electrodeposits has not been available.